Polar Aurora in Italy, why do we see it and why is it pink?

(Photo by Marco Rovecchi) ROME – An epochal event that left the whole of Italy and beyond speechless. The pink Aurora Polaris that we were able to admire with the naked eye this night (and above all photograph) is a spectacular phenomenon that has always fascinated man due to its colors that illuminate the night skies. “A […]

(Photo by Marco Rovecchi)

ROME – An epochal event that left the whole of Italy and beyond speechless. L‘The pink polar Aurora at night we were able to admire with the naked eye (and above all photograph) it is a spectacular phenomenon that has always fascinated man due to its colors that illuminate the night skies. “Depending on the hemisphere in which it occurs, we speak of ‘borealis’ or ‘southern’ aurora. For the ancients they were the ‘lights’ of the North or the South, but it was Galileo Galileo who used the definition of ‘Aurora borealis‘, combining the name of the Roman goddess of dawn, Aurora, with the Greek one used for the north wind, Boreas”, explains the Cnr.

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The polar Auroras, add the scientists, are generally visible at high latitudes, especially in the areas of the Arctic Circle, but, “in the presence of strong solar activity the quantity of particles that reach the Earth’s magnetosphere is such that occasionally the < strong>‘magnetic storm’ can also reach medium latitudesand in situations of exceptional activity of the Sun”, like that of this night, “the Aurora can reach the borders of Italy more intense in conjunction with magnetic storms caused by strong sunspot activity“.

The polar aurora, in fact, occurs when high-energy particles of the Sun collide with neutral atoms in our atmosphere: the energy emitted by this collision produces a show of lights which has fascinated man for centuries.

THE GEOMAGNETIC STORM THAT HIT ITALY< /h3>

The Space Weather Prediction Center of the US agency NOAA (National Oceanic and Atmospheric Administration) had already issued an alert yesterday for multiple solar flares that would hit the Earth between Friday and Saturday, causing a potentially ‘cannibalistic’ geomagnetic storm of class G3 (‘strong’) or G4 (‘severe’). What can you expect? In the worst case, malfunctions in electrical systems, interruptions in radio communications, in the best case only auroras visible even at low latitudes.

WHY THE AURORA NORTHERN IN ITALY IS PINK AND NOT GREEN?

“There are three main aspects that influence the color of the auroras – we read on the Cnr website – the gases that make up the atmosphere, the height at which they develop and the energy possessed by the solar wind particles.< strong> The most common color is green, emitted by oxygen hit by high-energy incident electrons (and therefore in the lower layers of the atmosphere), while for low-energy incident electrons oxygen emits red light. Nitrogen generally emits blue light. The fusion of these colors can lead to the presence of purple, pink, yellow and white in the auroras.

Height is also crucial: below 120 kilometers above the ground, the aurora will take on a blue or purple colour; between 120 and 180 kilometers it will have a dark green color; above 180 kilometers there will be an intense red color”.